Selectivity of the CID755673 analogs. Inhibition of PKCα (A), PKCβI (B), PKCδ (C), or CAMKIIα (D) by each of the 5 analogs was determined at 100 nM, 1 μM, and 10 μM concentrations. In the PKC assays, the potent PKC inhibitor GF109203X was used as a control. Data are the mean ± S.E.M. of three independent experiments. Statistical significance was determined using the unpaired t-test. ns, not statistically significant; *, p < 0.05; **, p < 0.01; ***, p < 0.001.